HOW LONG WILL THE COAL RESERVES OF 

 THE UNITED STATES LAST?* 



By Marius R. Campbell 

 Of the United States Geological Survey 



WITH the exception of food and 

 clothing, nothing concerns us 

 so mucli as fuel. On it we 

 depend for heat and light to make our- 

 selves comfortable, and for power by 

 which to bring within our reach all that 

 goes to make up the material part of our 

 twentieth-century civilization. Today 

 power is the mainspring of human activ- 

 ity ; with it modern civilization will flour- 

 ish — will expand and reach out to the 

 ends of the earth to minister to our pleas- 

 ures or to satisfy our ambitions ; without 

 it so-called civilization will cease to exist 

 and humanity will revert to the condition 

 of primitive man, with brute force as the 

 only dependence for safety and existence. 



If, therefore, power is the foundation 

 of all of the material things we consider 

 worth having, is it not well to stop our 

 mad race for a moment and consider 

 whence it comes and how much of the 

 raw material is available for future use? 



Without doubt, coal is the only fuel that 

 today is worth considering, and, so far as 

 we can see ahead, it will continue to be 

 the fuel of the future — at least so long as 

 it is within our reach or until other means 

 of power production shall supplant it. 

 Therefore any study of the fuel supply 

 of the future must be based upon a thor- 

 ough knowledge of coal, its mode of oc- 

 currence, amount from which future 

 supplies can be drawn, and rate of con- 

 sumption, past, present, and to come. 



The importance of the subject is 

 shown by the growing value of the coal- 

 mining industry in this country. In the 

 United States in 1905! coal to the 

 amount of 384,598,643 short tons, hav- 

 ing a value of $476,756,963, was mined. 



The value, compared with other mineral 

 products in the same year, is shown by 

 the following table : 



TABLE SHOWING VALUES OF MINERAL PRO- 

 DUCTS OF THE UNITED STATES FOR I905 



(1) Coal .... $476,756,96,^ 



(2) Iron . . . 382,450,000 



(3) Clay products . . 149,697,188 



(4) Copper . . . 139,795.716 



(5) Oil and gas . . 125,720,254 



(6) Gold and silver . 122,402,683 



At the present time the United States 

 is the largest factor in the world's pro- 

 duction of coal, as shown by the diagram 

 on page 130. 



In the diagram given above the pro- 

 duction of the three leading countries is 

 that for the year 1905 ; of the other coun- 

 tries figures for that year are not avail- 

 able, and the blocks in the diagram repre- 

 sent the production during either the 

 year 1904 or 1903. 



THE growth of coal 



Coal is derived from vegetable ma- 

 terial, either as accumulations in swamps 

 from plants growing iii situ or as wood 

 that has been drifted into basins. In 

 either case the accumulation of vegetable 

 matter has been covered by earthy ma- 

 terial washed ■ into the swamp or basin 

 and finally converted into coal. The for- 

 mer hypothesis is more generally ac- 

 cepted than the latter, and it seems to 

 apply to most of the coal beds of this 

 countr\'. 



The transformation from vegetable 

 matter into the different grades of coals 

 is a process not well understood, but it 

 seems to consist of the breaking up of 

 hydrocarbons and a partial slow distilla- 



*An address to the National Geographic Society, January 22, 1907. 



fAll statistics of production given in this paper are taken from U. S. Geological Survey, 

 Mineral Resources of the United States for 1905. 



